Khmer
At the moment theer are jus two manufacturer that have a 15mm khmer and cham range, Irregular and Outpost. Irregular have the advantage to have variety in miniature poses, but the miniatures are true 15mm. Outpost have single pose packs, with larger figures. It's a matter of personal tastes.
This army is all made with Outpost miniatures.
Khmer have a combination of troops that is unique: regular Ax, supported by Elephants, including the dreaded ElX.

The various generals that Khmer armies can field. In addition to the usual South eastern armies generals on elephant, there is also a weird light chariot

The main strike arm, the Elephants

More Elephants. These troops can be devastating but need to be carefully supported, because are quite brittle

The true elite of this army, ballistae mouned on elephants. In my club they are nicknamed Pak40

Long shield regular troops. The mainstay with the elephants

More Regular Auxilia

Round shield regular troops

Regular Blade fast. Shock infantry that well used can pierce the enemy line

Tribal Infantry

Javelin armed skirmishers

Skirmisher archers supporting the RAxS

More skirmishers, this time crossbow armed

Maiden Guard